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Abstract:

Systems for displaying images are provided. The system includes a display
device. The display device includes an array substrate, and a transparent
electrode stack overlaying the array substrate. The transparent electrode
stack includes a first electrode having a first slit, a second electrode
having an outer edge disposed corresponding to the interior of the first
slit, and a dielectric layer disposed between the first and second
electrodes. The dielectric layer electrically isolates the first and
second electrodes.

Claims:

1. A system for displaying images comprising a display device,
comprising:an array substrate; anda transparent electrode stack overlying
the array substrate, and comprising a first electrode comprising a first
slit, a second electrode comprising an outer edge disposed corresponding
to the interior of the first slit, and a dielectric layer disposed
between and electrically isolating the first electrode and the second
electrode.

2. The system as claimed in claim 1, wherein the outer edge is disposed
corresponding to a center line of the first slit.

3. The system as claimed in claim 1, whereinthe first electrode comprises
a plurality of first sub-electrodes; andthe first sub-electrodes are
connected to each other by a first connection electrode, and spaced from
each other by the first slit.

4. The system as claimed in claim 1, wherein the second electrode is
formed as an integral whole.

5. The system as claimed in claim 1, wherein:the second electrode
comprises a plurality of second sub-electrodes;the second sub-electrodes
are connected to each other by a second connection electrode, and spaced
from each other by a plurality of second slits; andthe outer edge is an
edge of at least one of the second sub-electrodes.

6. The system as claimed in claim 5, wherein the first slit is disposed
corresponding to at least one of the second slits.

7. The system as claimed in claim 5, wherein the first slit and the second
slits are all open slits.

8. The system as claimed in claim 5, wherein the first slit and the second
slits are all enclosure slits.

9. The system as claimed in claim 1, wherein the arrangement of the second
electrode is disposed below the first electrode.

10. The system as claimed in claim 1, further comprising a light shielding
layer disposed between the array substrate and an opposite substrate,
wherein the light shielding layer comprises an opening exposing parts of
the transparent electrode stack.

11. The system as claimed in claim 6, further comprising:an opposite
substrate disposed over the array substrate, and facing the transparent
electrode stack; anda liquid crystal layer disposed between the array
substrate and the opposite substrate.

12. The system as claimed in claim 1, further comprising an electronic
device, comprising:the display device; andan input unit coupled to the
display device and providing an input signal for the display device,
enabling the display device to display images.

13. The system as claimed in claim 12, wherein the electronic device is
selected from a group consisting of a cell phone, a digital camera, a
personal digital assistant (PDA), a notebook computer, a desktop
computer, a television, a car display, and a portable digital video disc
(DVD) player.

[0005]In general, a display device utilizing transverse electric field
technology driving liquid crystal molecules in a plane approximately
parallel to the substrate surface is suggested for improving a narrow
viewing angle problem of a widely used TN (twisted nematic) display
device.

[0006]Transverse electric field technology can be categorized into the
following technologies: IPS (In Plane Switching) technology and FFS
(Fringe Field Switch) technology. IPS technology arranges comb-shaped
pixel electrodes and comb-shaped common electrodes in a display. FFS
technology forms an insulating layer, which is sandwiched between a top
electrode layer and a bottom electrode layer on a same substrate in a
display. For FFS technology, one of the electrode layers is utilized as a
common electrode layer, and the other is utilized as a pixel electrode
layer. Slits, for example, are formed in the top electrode layer and
utilized as openings where an electrode field passes therethrough.

[0008]Thus, a system for displaying images is required to solve the
described problems.

BRIEF SUMMARY OF THE INVENTION

[0009]An embodiment of the invention provides a system for displaying
images. The system includes a display device. The display device includes
an array substrate, and a transparent electrode stack overlaying the
array substrate. The transparent electrode stack includes a first
electrode having a first slit, a second electrode having an outer edge
disposed corresponding to the interior of the first slit, and a
dielectric layer disposed between the first and second electrodes. The
dielectric layer electrically isolates the first and second electrodes.

[0010]Further scope of the applicability of the invention will become
apparent from the detailed descriptions given hereinafter. It should be
understood however, that the detailed descriptions and specific examples,
while indicating preferred embodiments of the invention, are given by way
of illustration only, as various changes and modifications within the
spirit and scope of the invention will become apparent to those skilled
in the Art from the detailed descriptions.

[0011]A detailed description is given in the following embodiments with
reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]The invention can be more fully understood by reading the subsequent
detailed description and examples with references made to the
accompanying drawings, wherein:

[0013]FIGS. 1A and 1B show an exemplary cross-section and a top view of a
pixel area of a display device of a first embodiment of the invention;

[0014]FIGS. 2A and 2B show an exemplary cross-section and a top view of a
pixel area of a display device of a second embodiment of the invention;

[0015]FIGS. 3A and 3B show an exemplary cross-section and a top view of a
pixel area of a display device of a third embodiment of the invention;

[0016]FIGS. 4A through 4C show graphs of transmittances in the pixel areas
of display devices of the first through third embodiments of the
invention;

[0017]FIG. 5 shows an exemplary top view of a pixel area of a display
device of a fourth embodiment of the invention;

[0018]FIG. 6 shows an exemplary top view of a transparent electrode stack
of a display device of a fifth embodiment of the invention; and

[0019]FIG. 7 schematically shows a system for displaying images of a
preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020]The following description is of the best-contemplated mode of
carrying out the invention. This description is made for the purpose of
illustrating the general principles of the invention and should not be
taken in a limiting sense. The scope of the invention is best determined
by reference to the appended claims.

[0021]Note that the concepts and specific practice modes of the invention
is described in detail by the embodiments and the attached drawings. In
the drawings or description, similar elements are indicated by similar
reference numerals and/or letters. Further, the element shape or
thickness in the drawings can be expanded for simplification or
convenience of indication. Moreover, elements which are not shown or
described can be in every form known by those skilled in the art.

[0022]It is understood that the following disclosure provides many
different embodiments, or examples, for implementing different features
of the invention. Specific examples of components and arrangements are
described below to simplify the present disclosure. These are, of course,
merely examples and are not intended to be limiting. For example, the
formation of a first feature over or on a second feature in the
description that follows may include embodiments in which the first and
second features are formed in direct contact, and may also include
embodiments in which additional features may be formed between the first
and second features, such that the first and second features may not be
in direct contact. In addition, the present disclosure may repeat
reference numerals and/or letters in the various examples.

[0023]In the subsequent description, phrases such as "substantially
parallel (to each other)", "substantially the same" and etc. . . . mean
expected to be parallel (to each other), the same and etc. in design, as
in practice, it is difficult to be mathematically or geometrically
parallel (to each other), the same and etc. Additionally, when deviation
is in an acceptable range of a corresponding standard or specification,
it is also recognized to be parallel (to each other), the same and etc.
Those skilled in the art are expected to acknowledge, that different
standards or specifications, depend upon various properties and
conditions, and thus, cannot be specifically listed.

[0024]Specific embodiments of the invention for fabrication of a pixel
area and a transparent electrode stack of a display device of a system
for displaying images are described. It is noted that the concepts of the
invention can be applied to any known or newly developed display device
and system for displaying images.

[0025]Referring to FIGS. 1A and 1B, a pixel area 1 of a display device 400
of a first embodiment of the invention is shown. FIG. 1A is a
cross-section plotted along the cross-section line I-I in FIG. 1B. The
display device 400 comprises an array substrate 100. A layer of scan
lines 10 and a layer of data lines 30 are disposed overlying the array
substrate 100. A dielectric layer (not shown) is disposed between the
layer of the scan line 10 and the layer of the data lines 30. The pixel
areas (including the pixel area 1) of the display device 400 are defined
by the vertical intersection of the scan lines 10 and the data lines 30.
A part of a scan line 30 serves as a gate electrode of a thin film
transistor. A semiconductor layer 20 is disposed overlying the gate
electrode, and a source electrode 30S and a drain electrode 30D are
disposed overlying the semiconductor layer 20. Thus forming a thin film
transistor. Further, the drain electrode 30D is electrically connected to
the corresponding data line 30 by a branch line 31.

[0026]A transparent electrode stack is disposed overlying the array
substrate 100, and a dielectric layer 132 is disposed between the
transparent electrode stack and the layer of the data lines 30. The
transparent electrode stack comprises a transparent first electrode 110,
a transparent second electrode 120, and a dielectric layer 131 disposed
between and isolating the electrodes 110 and 120. Further, the first
electrode 110 electrically connects to the source electrode 30S and acts
as a pixel electrode. The first electrode 110 comprises a plurality of
slits. In this embodiment, the first electrode 110 comprises one
connection electrode 115 and five sub-electrodes 116. The five
sub-electrodes 116 are connected to each other by the connection
electrode 115 and spaced from each other by four open slits 111, 112,
113, and 114. In other embodiments, the quantity and type (open or
enclosure) of the slits, and the quantity and type of the sub-electrodes
and the connection electrode of the first electrode 110 may depend on
requirements. The second electrode 120 is disposed below the first
electrode 110, and coupled to a common voltage source of the display
device 400, serving as a common electrode. The second electrode 120 has
neither openings nor slits, which means the second electrode 120 is
formed as an integral whole. Further, the first electrode 110 and the
second electrode 120 respectively partially overlap with the data lines
30.

[0027]The display device 400, such as a display panel, further comprises
an opposite substrate 200, a liquid crystal layer 300, and a light
shielding layer 210. The opposite substrate 200 and the array substrate
100 are oppositely disposed and spaced from each other. The liquid
crystal layer 300 is filled and disposed between the array substrate 100
and the opposite substrate 200. The light shielding layer 210 is disposed
overlying the opposite substrate 200, which is between the substrates 100
and 200. The light shielding layer 210 approximately overlaps the data
lines 30 (the extension of the light shielding layer 210 approximately
follows that of the data lines 30), and comprises at least one opening
211 exposing the pixel area 1 and parts of the transparent electrode
stack not overlapping the data lines 30. Further, at least one slit of
the first electrode 110 is disposed corresponding to the opening 211.

[0028]The transmittance in the pixel area 1 of the display device 400
shown in FIG. 1A is shown in FIG. 4A. The area 55 in FIG. 4A corresponds
to the area in FIG. 1A affected by the light shielding effects of the
light shielding layer 210. The x-axis scales of FIG. 4A correspond to the
left-to-right width position of the pixel area 1. The y-axis scales of
FIG. 4A indicate the transmittance values. The curve 51 in FIG. 4A
indicates the transmittances of every position of the pixel area 1 shown
in FIG. 1A. FIG. 4A shows the average transmittance (Avg T) of the pixel
area 1 is 72.83%.

[0029]Referring to FIGS. 2A and 2B, a pixel area 2 of a display device 400
of a second embodiment of the invention is shown. FIG. 2A is a
cross-section plotted along the cross-section line II-II in FIG. 2B. In
some cases, a second electrode 140 in the pixel 2 can replace the second
electrode 120 in the pixel 1 shown in FIGS. 1A and 1B.

[0030]Only the outer edge of the second electrode 140 of the pixel area 2
of the second embodiment is different from the pixel area 1 of the first
embodiment. In FIGS. 2A and 2B, an outer edge 140a of a second electrode
140 is disposed corresponding to the interior of the slit 111 of the
first electrode 110, and disposed beyond the two edges of the slit 111
(which means the outer edge 140a fails to overlap the two edges of the
slit 111). The two edges of the slit 111 are substantially parallel to
the extension direction of the data lines 30. The outer edge 140a may be
disposed along the middle of the slit 111 (that is, the outer edge 140a
is disposed corresponding to a center line of the slit 111). Further, an
outer edge 140b of the second electrode 140 may also be disposed
corresponding to the interior of the slit 114 of the first electrode 110.
The outer edge 140b may be disposed along the middle of the slit 114.
That is, the outer edges 140a and 140b of the second electrode 140 of the
second embodiment are respectively disposed corresponding to the interior
of the slits 111 and 114 of the first electrode 110. In other
embodiments, one of the outer edges 140a and 140b of the second electrode
140 may extend over the neighboring data line 30 as the corresponding
edge of the second electrode 120 as shown in FIG. 1B. In this embodiment,
further, the outer edges 140a and 140b of the second electrode 140 are
both substantially parallel to the extension direction of the data lines
30.

[0031]The transmittance in the pixel area 2 of the display device 400
shown in FIG. 2A is shown in FIG. 4B where a curve 52 indicates the
transmittances of every position of the pixel area 2. Compared to the
curve 51 shown in FIG. 4A, values of troughs, whose orthographic
projections on an x-axis are near the positions corresponding to those of
the outer edges 140a and 140b of the second electrode 140 in FIG. 2A, of
the curve 52 (such as those indicated by dotted circles in FIG. 4B),
increase relative to the values of troughs at the corresponding positions
of the curve 51. Thus, the transmittance variance in the pixel area 2
decreases, and the average transmittance of the pixel area 2 increases.
For example, FIG. 4B shows the average transmittance of the pixel area 2
at 75.83%, greater than 72.83% of the pixel area 1.

[0032]Referring to FIGS. 3A and 3B, a pixel area 3 of a display device 400
of a third embodiment of the invention is shown. FIG. 3A is a
cross-section plotted along the cross-section line III-III in FIG. 3B. In
some cases, a second electrode 150 in the pixel 3 can replace the second
electrode 120 in the pixel 1 shown in FIGS. 1A and 1B or the second
electrode 140 in the pixel 2 shown in FIGS. 2A and 2B. The pixel area 3
of the third embodiment is different from the pixel area 2 of the second
embodiment in that the second electrode 150 in the pixel area 3 comprises
a plurality of slits. In this embodiment, the second electrode 150
comprises one connection electrode 155 and three sub-electrodes 156. The
three sub-pixels 156 are connected to each other by the connection
electrode 155, and spaced from each other by the two open slits 151 and
152. In other embodiments, the quantity and type (open or enclosure) of
the slits, and the quantity and type of the sub-electrodes and the
connection electrode of the second electrode 150 may depend on
requirements. Further, compared to the second electrode 140 shown in
FIGS. 2A and 2B, the increased "edges" due to formation of slits between
the sub-electrodes 156 of the second electrode 150 are considered the
outer edges of the second electrode 150.

[0033]As shown in FIG. 3B, the slits 151 and 152 of the second electrode
150 are respectively disposed corresponding to the slits 112 and 113 of
the first electrode 110. The outer edges 151b and 152b of the second
electrode 150 respectively along the length directions of the slits 151
and 152 are respectively disposed corresponding to the interior of the
slits 112 and 113. The outer edges 151b and 152b may be respectively
disposed along the center lines of the slits 112 and 113. In this
embodiment, the widths of the slits 151 and 152 are substantially the
same as those of the slits 111 through 114. In other embodiments, the
widths of the slits 151 and 152 can be greater than those of the slits
111 through 114. In some cases, for example, the slits 151 and 152 can be
between 1 and 2 times as wide as the slits 111 through 114. In some
cases, the slits 151 and 152 can be numerically wider than the slits 111
through 114. In one embodiment, for example, the slits 111 through 114
are as wide as 3 μm, while the slits 151 and 152 are wider than 3
μm.

[0034]In this embodiment, further, only one outer edge 150a of all of the
edges of the second electrode 150 orthographically projects on the
interior of the slit 111 of the first electrode 110, for example.
Moreover, only one outer edge 151b of one slit 151 orthographically
projects on the interior of the slit 112 of the first electrode 110, for
example.

[0035]The transmittance in the pixel area 3 of the display device 400
shown in FIG. 3A is shown in FIG. 4c where a curve 53 indicates the
transmittances of every position of the pixel area 3. Compared to the
curves 51 and 52 shown in FIGS. 4A and 4B, values of troughs, whose
orthographic projections on an x-axis are near the positions
corresponding to those of the outer edges 150a, 151b, 152b, and 150b of
the second electrode 150 in FIG. 3A, of the curve 53 (such as those
indicated by dotted circles in FIG. 4c) are apparently increased relative
to the values of troughs at the corresponding positions of the curves 51
and 52. Thus, the transmittance variance in the pixel area 3 decreases,
and the average transmittance of the pixel area 3 increases. For example,
FIG. 4c shows the average transmittance of the pixel area 3 at 77.07%,
greater than those of the pixel areas 1 and 2.

[0036]In the device of the fourth embodiment shown in FIG. 5, compared to
the device of the third embodiment, the size of the first electrode 110
is reduced, and no longer overlaps the data lines 30. A pair of outer
edges 151a and 151b, along the length direction of the slit 151, of the
second electrode 150 are respectively disposed corresponding to the
interior of the two slits 111 and 112 of the first electrode 110. A pair
of outer edges 152a and 152b, along the length direction of the slit 152,
of the second electrode 150 are respectively disposed corresponding to
the interior of the two slits 114 and 113 of the first electrode 110. The
respective corresponding mode between the outer edges of the second
electrode 150 and the slits of the first electrode 110 is the same as or
equivalent to that between the outer edge 140a of the second electrode
140 and the slits of the first electrode 110 described for and shown in
FIG. 2A. In this embodiment, further, the outer edge 150a (or 150b) is
disposed corresponding to one sub-electrode 116 of the first electrode
110. In other words, the outer edge 150a (or 150b) orthographically
projects on one sub-electrode 116.

[0037]In the fifth embodiment of the invention, the first electrode 110
shown in FIG. 3B or 5 is replaced by a transparent electrode 810
comprising enclosure slits 811, 812, 813, and 814 shown in FIG. 6, and
the second electrode 150 shown in FIG. 3B or 5 is replaced by a
transparent electrode 820 comprising enclosure slits 821 and 822 shown in
FIG. 6. The corresponding mode of relative positions between the
transparent electrodes 810 and 820 is the same as or equivalent to that
of relative positions between the electrodes 110 and 150 shown in FIG. 3B
or 5. The slits 811 and 812 are substantially parallel to each other, and
the slits 813 and 814 are substantially parallel to each other, but the
slits 812 and 813 are not parallel. A pixel area comprising the
transparent electrodes 810 and 820 is called "dual domain". A pixel area
comprising the transparent electrode 820 and modified transparent
electrode 810 comprising substantially parallel slits 811, 812, 813, and
814 is called "mono domain". Further, the profile of the transparent
electrode 820 may be modified to have two tapered outer edges
respectively disposed corresponding to the interior of the slits 811 and
814, and substantially parallel to directions of the slits 811 and 814.

[0038]As shown in FIG. 7, the display device 400 can be assembled with an
input unit 500 to fabricate different kinds of the electronic device 600.
The display device may comprise only one type of the described pixel
areas 1, 2, 3, and 4, or any combination of the described pixel areas 1,
2, 3, and 4. The input unit 500 is coupled to the display device 400,
inputting signals, such as image signals, into the display device 400 for
image generation and display. The electronic device 600 can be a cell
phone, a digital camera, a personal digital assistant (PDA), a notebook
computer, a desktop computer, a television, a car display, or a portable
digital video disc (DVD) player.

[0039]While the invention has been described by way of example and in
terms of preferred embodiment, it is to be understood that the invention
is not limited thereto. To the contrary, it is intended to cover various
modifications and similar arrangements (as would be apparent to those
skilled in the Art). Therefore, the scope of the appended claims should
be accorded the broadest interpretation so as to encompass all such
modifications and similar arrangements.